1,221 research outputs found

    Probing the physics of newly born magnetars through observation of superluminous supernovae

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    The central engines of some superluminous supernovae (SLSNe) are generally suggested to be newly born fast rotating magnetars, which spin down mainly through magnetic dipole radiation and gravitational wave emission. We calculate the magnetar-powered SLSNe light curves (LCs) with the tilt angle evolution of newly born magnetars involved. We show that, depending on the internal toroidal magnetic fields Bˉt{\bar B}_{\rm t}, the initial spin periods PiP_{\rm i}, and the radii RDUR_{\rm DU} of direct Urca (DU) cores of newly born magnetars, as well as the critical temperature TcT_{\rm c} for 3P2^3P_2 neutron superfluidity, bumps could appear in the SLSNe LCs after the maximum lights when the tilt angles grow to π/2\pi/2. The value of TcT_{\rm c} determines the arising time and the relative amplitude of a bump. The quantity RDUR_{\rm DU} can affect the arising time and the luminosity of a bump, as well as the peak luminosity of a LC. Moreover, it is interesting that a stronger Bˉt{\bar B}_{\rm t} will lead to both a brighter peak and a brighter bump in a LC. While keeping other quantities unchanged, the bump in the LC disappears for the magnetar with smaller PiP_{\rm i}. We suggest that, once the SLSNe LCs with such kinds of bumps are observed, by fitting these LCs with our model, not only BdB_{\rm d} and PiP_{\rm i} of newly born magnetars but also the crucial physical quantities Bˉt{\bar B}_{\rm t}, RDUR_{\rm DU}, and TcT_{\rm c} could be determined. Nonobservation of SLSNe LCs with such kinds of bumps hitherto may already put some (\textit{though very rough}) constraints on Bˉt{\bar B}_{\rm t}, PiP_{\rm i}, RDUR_{\rm DU}, and TcT_{\rm c}. Therefore, observation of SLSNe LCs may provide a new approach to probe the physics of newly born magnetars.Comment: 9 pages, 4 figures, to appear in PR

    Description of 178^{178}Hfm2^{m2} in the constrained relativistic mean field theory

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    The properties of the ground state of 178^{178}Hf and the isomeric state 178^{178}Hfm2^{m2} are studied within the adiabatic and diabatic constrained relativistic mean field (RMF) approaches. The RMF calculations reproduce well the binding energy and the deformation for the ground state of 178^{178}Hf. Using the ground state single-particle eigenvalues obtained in the present calculation, the lowest excitation configuration with Kπ=16+K^\pi=16^+ is found to be ν(7/2[514])1(9/2+[624])1\nu(7/2^-[514])^{-1}(9/2^+[624])^{1} π(7/2+[404])1(9/2[514])1\pi(7/2^+[404])^{-1}(9/2^-[514])^{1}. Its excitation energy calculated by the RMF theory with time-odd fields taken into account is equal to 2.801 MeV, i.e., close to the 178^{178}Hfm2^{m2} experimental excitation energy 2.446 MeV. The self-consistent procedure accounting for the time-odd component of the meson fields is the most important aspect of the present calculation.Comment: 12 pages(preprint), 2 figures, 1 tabl

    Remarks on Hawking radiation as tunneling from the BTZ black holes

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    Hawking radiation viewed as a semiclassical tunneling process from the event horizon of the (2 + 1)-dimensional rotating BTZ black hole is carefully reexamined by taking into account not only the energy conservation but also the conservation of angular momentum when the effect of the emitted particle's self-gravitation is incorporated. In contrast to previous analysis of this issue in the literature, our result obtained here fits well to the Kraus-Parikh-Wilczek's universal conclusion without any modification to the Bekenstein-Hawking area-entropy formulae of the BTZ black hole.Comment: 12pages, no figure, use JHEP3.cls. Version better than published one in JHE

    Anomalies and de Sitter radiation from the generic black holes in de Sitter spaces

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    Robinson-Wilczek's recent work shows that, the energy momentum tensor flux required to cancel gravitational anomaly at the event horizon of a Schwarzschild-type black hole has an equivalent form to that of a (1+1)-dimensional blackbody radiation at the Hawking temperature. Motivated by their work, Hawking radiation from the cosmological horizons of the general Schwarzschild-de Sitter and Kerr-de Sitter black holes, has been studied by the method of anomaly cancellation. The result shows that the absorbing gauge current and energy momentum tensor fluxes required to cancel gauge and gravitational anomalies at the cosmological horizon are precisely equal to those of Hawking radiation from it. It should be emphasized that the effective field theory for generic black holes in de Sitter spaces should be formulated within the region between the event horizon (EH) and the cosmological horizon (CH), to integrate out the classically irrelevant ingoing modes at the EH and the classically irrelevant outgoing modes at the CH, respectively.Comment: 14 pages without figure, use elsart.cls, to appear in Phys.Lett.

    Pseudospin symmetry and its approximation in real nuclei

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    The origin of pseudospin symmetry and its broken in real nuclei are discussed in the relativistic mean field theory. In the exact pseudospin symmetry, even the usual intruder orbits have degenerate partners. In real nuclei, pseudospin symmetry is approximate, and the partners of the usual intruder orbits will disappear. The difference is mainly due to the pseudo spin-orbit potential and the transition between them is discussed in details. The contribution of pseudospin-orbit potential for intruder orbits is quite large, compared with that for pseudospin doublets. The disappearance of the pseudospin partner for the intruder orbit can be understood from the properties of its wave function.Comment: 10 pages, 3 figure

    Hawking radiation from (2+1)-dimensional BTZ black holes

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    Motivated by the Robinson-Wilczek's recent viewpoint that Hawking radiation can be treated as a compensating energy momentum tensor flux required to cancel gravitational anomaly at the horizon of a Schwarzschild-type black hole, we investigate Hawking radiation from the rotating (2+1)(2+1)-dimensional BTZ black hole and the charged (2+1)(2+1)-dimensional BTZ black hole, via cancellation of gauge and gravitational anomalies at the horizon. To restore gauge invariance and general coordinate covariance at the quantum level, one must introduce the corresponding gauge current and energy momentum tensor fluxes to cancel gauge and gravitational anomalies at the horizon. The results show that the values of these compensating fluxes are exactly equal to those of (1+1)(1+1)-dimensional blackbody radiation at the Hawking temperature.Comment: 15 pages; references updated and added; to appear in Phys. Lett.

    The Penetration of Scientific Frontier in Solid State Physics Teaching

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    Solid State Physics is a core course in undergraduate physics education and its content is closely linked to the frontiers of research in condensed matter physics. The introduction of appropriate scientific frontier advances in teaching can broaden students’ academic horizons and motivate them to study in depth and engage in research. In this study, we combine the teaching content in solid state physics and integrate cutting-edge scientific research into the teaching of solid state physics, to provide a theoretical reference for future physics courses that can be high order, innovative and challenging
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